Question

When a p-n junction diode is forward biased:

• A. The barrier height and the depletion layer width both increase.
• B. The barrier height increases and the depletion layer width decreases.
• C. The barrier height and the depletion layer width both decrease.
• D. The barrier height decreases and the depletion layer width increases.

Hint:

In a forward-biased p-n junction, the applied voltage decreases the potential barrier and narrows the depletion region, allowing current to flow.

Answer 1

The Correct Option is C

In a p-n junction diode, understanding the effects of forward biasing is crucial. When a diode is forward biased, the following occurs: 

• Barrier Height: The external voltage applied in forward biasing reduces the built-in potential barrier. This lowering of the barrier makes it easier for charge carriers to cross the junction.
• Depletion Layer Width: Forward biasing reduces the depletion layer width. As the potential barrier decreases, more charge carriers can move across the junction, thus narrowing the depletion region.

This makes the correct answer: The barrier height and the depletion layer width both decrease.